Automatic oiler for chain saws



Sept. 29, 1970 G. J. SHAW EI'AL 3,530,957

AUTOMATIC OILER FOR CHAIN SAWS Filed Oct. 9,- 1968 2 Sheets-Sheet l INVENTOESZ GERALD J. SHAW LLOVD' HQTUGGLE BY e/Vm, Kind,

Sept. 29, 1970 G. J. SHAW HAL 3,530,957

AUTOMATIC OILER FOR CHAIN SAWS FiledOct. 9, 1968 2 Sheets-Sheet B INVENTOESS GEEALD J. SHAW LLOVD H. TUGGLE BY Wm, afM-m,

9' 3mm! M United States Patent 3,530,957 AUTOMATIC OILER FOR CHAIN SAWS Gerald J. Shaw and Lloyd H. Tuggle, Shreveport, La., assignors to Baird-Pouland Inc., Shreveport, La., a corporation of Delaware Filed Oct. 9, 1968, Ser. No. 766,135 Int. Cl. F16n 13/14 US. Cl. 184-15 3 Claims ABSTRACT OF THE DISCLOSURE An oil pump operatively associated with the centrifugal clutch of a chain saw; the pump including a system of cams, levers and check valves which, when activated by the engagement of the clutch, moves a quantity of oil from a reservoir and discharges the same as a lubricant on the cutting chain. An outstanding feature of the pump is the means of reducing the speed between that of the engine and the reciprocating stroke of the pump.

The present invention pertains to an automatic oiler particularly adapted for use on a gasoline engine driven chain saw to automatically supply a quantity of oil to a cutting chain when the saw is in use.

One of the objects of the invention is to provide for the positive delivery of oil from a reservoir to the saw chain.

Another object is the provision of a unique speed-reducing pump mechanism whereby the speed of operation of the pump is reduced considerably from the normal operating speed of the engine.

A still further object of the invention is the provision of an oiler mechanism which is simple in its construction and can be manufactured with a minimum of cost.

Further objects and advantages of the invention will become apparent in the course of the following detailed description when viewed together with the accompanying drawings in which:

FIG. 1 is a broken, sectional view of only that portion of a power driven chain saw which shows the present invention in an automatic pump and its related saw part members.

FIG. 2 is a vie-w of the main pump gear of the invention.

FIG. 3 is an isometric view of a cam which is used as a piston displacement element.

FIG. 4 is a broken side view of the pumping unit showing more clearly how the rotation of the engine is used to operate the pump.

FIG. 5 shows a pump lever actuated by the aformentioned cam.

FIG. 6 is a view illustrating the relationship of the oil discharge hole with respect to a chain saw guide bar and sprocket.

FIG. 7 shows the pump unit as mounted on a typical frame having a conventional mounting pad adapted to receive the aforementioned chain guide bar.

FIG. 8 is an isometric view of the pump cover which shows the integrally formed gear teeth for use with the pump gear.

DESCRIPTION OF ILLUSTRATED EMBODIMENT In the drawing, more particularly in FIG. 1, numeral 10 designates the conventional crankshaft in a chain saw of the present type. The shaft is rotatably journaled in bearings 11 and 12 which are suitably positioned in a crankcase 13.

Mounted over a projecting lip 14 on the crankcase 13 is an oil tank designated generally by the numeral 15 and having an oil reservoir 16 and a cover plate 16.

\Mounted on the crankshaft 10 just outside the crankcase 13 is a cam 18 more clearly illustrated in FIG. 3. Abutting the outside face of the cam 18 is a bearing 19 with a washer-spacer 20' between its outer face and a centrifugally operable clutch 21. The clutch 21 is threaded on the crankshaft 10 so that the bearing 19 and the cam- 18 are held rigidly and made to rotate with the crankshaft 10.

A clutch drum 22 and chain driving sprocket 23 are silver soldered together as a unit and mounted for free rotation on the bearing 19. Thus, when the crankshaft reaches a given speed of rotation, the expandable clutch 21, operating by centrifugal force, engages the inner face of the drum 22 and rotates it and the sprocket 23.

By reference to FIG. 6 it can now be seen that the sprocket 23 is then made to drive an endless cutting chain 24 around a guide bar 25 for cutting wood.

Reference is again made to FIG. 1 which shows a special gear 26 mounted for free rotation on the aforementioned cam 18. The gear is illustrated separately in FIG. 2 which shows the gear as having a cam surface 27 on one face thereof.

A pump cover 28 is shown in detail in FIG. 8. In this figure the cover is shown as provided with internally formed teeth 29 arranged to enmesh with the teeth of the special gear 26 when the gear and cover are mounted as shown in FIG. 7. The meshing of these two gears is one of the features of the present invention and is illustrated in FIG. 4 of the drawings. Here, the cover 28 is broken away to show the teeth of the special gear 26 enmeshed with the teeth 29 of the cover 28. In the present arrangement the cover teeth 29 are 20 in number while the special gear is provided with 19 teeth; so that the meshing arrangement must assume the configuration shown in FIG. 4. Note that with the special gear 26- mounted on the cam 18, there is only one tooth of the gear in actual engagem ent at a time. In other words, as the crankshaft revolves the cam 18 at engine speed in one direction or rotation, the special gear only advances one tooth per revolution of the shaft but in the opposite direction. Hence, a 20:1 reduction is effected in this simple twogear arrangement.

Note, in FIG. 8, that the cover 28 is also provided with a recess 30 having a projection 31 integrally formed with the casting and serving as a fulcrum for a lever 32 as illustarted in detail in FIG. 5. The lever is provided with a wear button 33, the purpose of which will be subsequently described.

Reference is made again to FIG. 1 which shows the wear button 33 of the lever 32 resting against the high side of the face cam 26 and the opposite end of the lever resting against a pump piston 34 which is normally urged against the lever by means of a compression spring 35. Thus, as the special gear 26 is rotated, the lever 32 will be actuated in the above-described manner and as illustrated by the dotted lines to give a reciprocatory movement to the pump piston 34.

Also in FIG. 1, a weighted oil pick-up 36 is suspended in the oil reservoir by means of a flexible tube 37 affixed to a fitting 38. An intake valve 39 and an outlet valve 40 are employed and flow passageways are drilled as shown so that, as the piston 34 is moved forward and backward in reciprocatory motion, oil is drawn from; the reservoir and exhausted through the outlet check valve 40.

The configuration on the front end of the oil tank 15 is fairly general with all saws of the direct drive type. In FIG. 7, the mounting pad 41 for the guide bar includes an oil groove 42 and mounting studs 43. The oil groove is extended along the flat face of the guide bar mounting pad 41 and is in communication with the oil discharge valve '40. In FIG. 6 a hole 44 in the guide 3 bar 25 is in communication which permits oil to be pumped against the revolving chain 24 regardless of any forward or backward adjustment given to the bar;

While we have described the invention in deail in a particular embodiment, it is to be understood that this has been by way of example only, and that changes in actual construction could be made without departing from the spirit and scope of the invention as defined by the following claims.

What is claimed as invention is:

1. In an automatically operable lubricating pump, a chain saw driven by a gasoline engine and having an oil tank reservoir, a sleeve-type cam mounted on the crankshaft of said engine and adapted to rotate therewith, a spur-type gear mounted for free rotation on said cam, a pump piston in said tank, passageways in said oil tank communicating with said pump and a cutting chain operated by said saw, check valves in said passageways for the unidirectional flow of -oil from said tank reservoir, means responsive to the rotation of said spur-type gear for operating said pump piston, and means for reducing the speed of rotation of said spur-type gear with respect to the rotating speed of said crankshaft.

with the elongated-groove 42-- ducing the speed of rotation of said spur-type gear with respect to therotating speed of said engine comprises an internal gear formed integrally with a portion of said pump and wherein said internal gear has a greater number of teeth than the spur-type gear with which it is ged. to a i, s. a

3. The device of claim 1 wherein the means responsive to the rotation of said spur-type gear for the operation of said pump piston includes a cam surface on the face of said spur-typegear, a lever pivotally mounted approximately midway its. length with one end of said lever yabutting'said cam surface and the opposite end of said lever operatively engaging said pump piston.

References Cited UNITED STATES PATENTS MANUEL A. ANTONAKAS, Primary Examiner US. Cl. X.R. 143-32; 184-27 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, Dated September 29,

lnventofls) Gerald J Shaw et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 4, "Baird-Pouland Inc." should read Beaird-Poulan, Inc.

Signed and sealed this 20th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents USCOMM-DC GUSTO-P69 FORM P0-105D (10-69) a n.5, covznrmzvn nmn'mc ornc: u" o-sn-au 

